1. Field of the Invention
The present invention is directed to multi-channel cabling for distributing radio frequency (RF) signals. In particular, the present invention is directed to laminated multi-channel coaxial (coax) cabling for distributing radio frequency (RF) signals within a structure or building.
2. Background
The continuing expansion of wireless communication and its accompanying wireless technology will require many more “cell sites” than are currently deployed. This expansion has been estimated from a doubling to a ten-fold increase in the current number of cell sites, particularly in the deployment of 4G/LTE (long term evolution) networks. This dramatic increase in the number of cell sites is due, at least in part, to the high bandwidth demand for wireless applications, where the bandwidth of a given cell site must be shared with all available UE (user equipment) within range of the site.
Better wireless communication coverage is needed to provide the desired bandwidth to an increasing number of customers. Thus, in addition to new deployments of traditional, large “macro” cell sites, there is a need to expand the number of “micro” cell sites (sites within structures, such as office buildings, schools, hospitals, and residential units). In-Building Wireless (IBW) Distributed Antenna Systems (DASs) are utilized to improve wireless coverage within buildings and related structures. Conventional DASs use strategically placed antennas or leaky coaxial cable (leaky coax) throughout a building to accommodate radio frequency (RF) signals in the 300 MHz to 6 GHz frequency range. Conventional RF technologies include TDMA, CDMA, WCDMA, GSM, UMTS, PCS/cellular, iDEN, WiFi, and many others.
Outside the United States, carriers are required by law in some countries to extend wireless coverage inside buildings. In the United States, bandwidth demands and safety concerns will drive IBW applications, particularly as the world moves to current 4G architectures and beyond.
There are a number of known network architectures for distributing wireless communications inside a building. These architectures include choices of passive, active and hybrid systems. Active architectures generally include manipulated RF signals carried over fiber optic cables to remote electronic devices which reconstitute the electrical signal and transmit/receive the signal. Passive architectures include components to radiate and receive signals, usually through a punctured shield leaky coax network. Hybrid architectures include native RF signal carried optically to active signal distribution points which then feed multiple coaxial cables terminating in multiple transmit/receive antennas. Specific examples include analog/amplified RF, RoF (Radio over Fiber, also known as RFoG, or RF over glass), fiber backhaul to pico and femto cells, and RoF vertical or riser distribution with an extensive passive coaxial distribution from a remote unit to the rest of the horizontal cabling (within a floor, for example). These conventional architectures can have limitations in terms of electronic complexity and expense, inability to easily add services, inability to support all combinations of services, distance limitations, or cumbersome installation requirements.
Conventional cabling for IBW applications includes RADIAFLEX™ cabling available from RFS (www.rfsworld.com), standard ½ inch coax for horizontal cabling, ⅞ inch coax for riser cabling, as well as, standard optical fiber cabling for riser and horizontal distribution.
Physical and aesthetic challenges exist in providing IBW cabling for different wireless network architectures, especially in older buildings and structures. These challenges include gaining building access, limited distribution space in riser closets, and space for cable routing and management.